The invention relates to a multi-caliber firearm having a breech and a device for varying the effective diameter of the breech to accommodate ammunition having different cartridge base diameters.
A multi-caliber pistol which can be converted to different projectile calibers by exchanging the barrel is described in German utility model 8709136. Since the cartridges used for the various barrels also differ in terms of the diameter of the cartridge base, a resilient holding claw is provided in the known pistol which is arranged on the side located opposite the pull-out claw of the breech and which constitutes an elastically flexible abutment for the edge of the cartridge base. The pull-out system of the breech is thus automatically matched to the particular diameter of the cartridge base, so that one and the same breech can be used for all types of ammunition.
In this known solution, however, the production and assembly of the resilient holding claw involve a relatively high outlay. The contour of the holding claw and the elastic pressing force of this holding claw have to be carefully coordinated, so as to guarantee that the pull-out system functions perfectly.